Around Christmas, Ronna Martin (Sarah Polley), working overtime at her supermarket job to avoid being evicted, is approached at work by Adam (Scott Wolf) and Zack (Jay Mohr), who ask if they can buy 20 hits of ecstasy. They were hoping to buy from her co-worker, Simon Baines (Desmond Askew), but he is in Las Vegas. Realizing she can profit from the deal, Ronna approaches Simon's dealer, Todd Gaines (Timothy Olyphant), for the drugs but, as she is unable to pay the full amount, leaves her friend and other co-worker, Claire Montgomery (Katie Holmes), with Todd as collateral while she makes her deal. Before she can give Adam and Zack the drugs, Ronna grows suspicious of Burke (William Fichtner), a stranger with the two who presses her for the ecstasy. In a panic, she flushes the drugs down the toilet and leaves. Ronna then steals aspirin to replace the ecstasy she disposed of, helped by her friend and another coworker, Manny (Nathan Bexton), who swallowed two of the pills without knowing their strength. Ronna gives 20 of the fake pills to Todd, and she, Claire, and Manny make their way to a rave, where she sells other over-the-counter pills she stole as ecstasy. Todd soon discovers the pills are fake and pursues Ronna, discovering her at the rave. Ronna flees with Manny, but he is overcome by the drugs. Ronna leaves him in an alley and promises to return with her car, but Todd confronts her with a gun in the parking lot. Before he can shoot Ronna, she is hit by a car that speeds away.
The story restarts from the perspective of Simon, who is on a trip to Las Vegas with Marcus (Taye Diggs), Tiny (Breckin Meyer), and Singh (James Duval). Tiny and Singh soon get food poisoning, leaving Simon and Marcus to their own devices. Simon crashes a wedding and has sex with two of the bridesmaids before their hotel room accidentally catches fire. Simon and Marcus leave the hotel, stealing a car from someone who thinks Marcus is a parking attendant. The pair goes to a strip club, where Simon orders a private lap dance for them using Todd's loaned credit card, but he enrages the bouncer, Victor Jr., by groping one of the strippers. Simon shoots Victor Jr. with a gun that he found in the stolen car, and he and Marcus flee to the hotel, rousing Tiny and Singh. The four barely escape the bouncer and his father, Victor Sr. (J. E. Freeman), but Victor Sr. traces Todd's address from the credit card Simon left at the strip club.
The story then changes perspective to Adam and Zack, actors in a daytime soap opera who are secretly in a relationship. Having been busted for drug possession, they are forced to work with Burke, a police detective, to entrap their dealer. Adam is fitted with a wire. When they cannot find their usual dealer, Simon, the two convince Ronna to come up with the drugs. When Ronna arrives later to make the deal, Zack has a change of heart and secretly warns her away, leading her to dispose of the drugs in the bathroom. After the unsuccessful bust, Burke invites Adam and Zack to Christmas dinner, where they observe strange behavior from Burke and his wife, Irene. Burke and Irene finally pitch an Amway-type company to the two over dinner, but the pair make excuses and leave. Idly discussing their mutual infidelities, Adam and Zack realize they both cheated with the same person, Jimmy. They discover he is at a rave and confront him there, cutting his long hair. While leaving the rave, they accidentally run over Ronna in the parking lot, panicking and driving away when they see Todd with a gun. Zack tries to reassure Adam that, even if Ronna had survived being run over, Todd would have shot her. Adam then discovers to his horror that he is still wearing his wire. Fearing they have been recorded and will be discovered, the two return to the accident scene to remove Ronna's body, but discover she is still alive. They prop her up on a car, setting off its alarm, and watch from a distance as other partygoers call for an ambulance.
As morning breaks, Claire goes to a restaurant where she hopes to meet up with Ronna and Manny, but sees Todd instead. The two end up talking and going back to Todd's apartment building. While making out on the stairs, they are confronted by Victor Jr. and Sr. Todd offers Simon's address just as Simon arrives, having hoped to hide for a few days. There is a scuffle but it is stopped by Claire, who refuses to witness a murder. As a form of "justice," Simon agrees to be shot in the arm by Victor Jr. as Claire leaves in disgust.
Meanwhile, Ronna wakes up in a hospital and hobbles back to the supermarket, where Claire is also working. Realizing she left Manny at the rave, Ronna returns with Claire to the venue to find Manny pale and shaken in an alley. The three go to Ronna's car, where Ronna muses she can now pay her rent. Manny asks, to the incredulity of Ronna and Claire, what their plans are for New Year's.
John August originally wrote the portion of the story involving Ronna as a short film titled X, inspired by the "Rock 'n' Roll Ralphs" grocery store on Sunset Boulevard. After friends asked about Simon's trip to Vegas, and what was going on with Adam and Zack, he wrote two more parts, accounting for the nature of the film. After viewing Swingers, John August and the producers felt director Doug Liman would be the perfect fit, and Liman signed on soon thereafter. Polley, who resides in Canada, was offered the role directly, without auditioning. Olyphant was a late addition; he was about to shoot the film Practical Magic but was fired from his role and replaced by Aidan Quinn, enabling him to join the cast as Todd. He was called in to audition for Adam or Zack, but all agreed he was better as drug dealer Todd, the character he wanted to play. When Go was about to start shooting, its foreign financing fell through because the film lacked a "bankable white male star." Columbia Pictures stepped in and financed the film. As most of the plot takes place at night, August recalled being "outside in the dark from 8 p.m. until 8 a.m. for 25 days" during filming.
Go was released to critical acclaim. The film received a 92% "fresh" rating from Rotten Tomatoes based on 72 critic reviews with an average score of 7.6/10. The site's consensus reads: "With its sharp dialogue and raucous visuals, Go entertains at an exhilarating pace." Many critics generally found Go's fast pace and light-hearted feel appealing. The film grossed $28.5 million worldwide against a $20 million budget.
Because of its irreverent and frequently off-topic dialogue, fast pace, rapidly changing point of view, and non-chronological format, the film is generally categorized as one of many movies of varying quality that attempted to capture the same style of Quentin Tarantino's Pulp Fiction. Leonard Maltin, who disliked the film, said that Go came off as a "junior Pulp Fiction." However, unlike many of the films in the subgenre, the comparisons were mostly favorable, with Roger Ebert of the Chicago Sun-Times stating that "Go is an entertaining, clever black comedy that takes place entirely in Tarantino-land.... Go has energy and wit, and the performances are right for the material – especially Sarah Polley, who thinks fast and survives harrowing experiences, and Fichtner, the cop who is so remarkably open to new experiences."
Janet Maslin of The New York Times praised the performances of Olyphant and Fichtner, as well as Go's energy and Liman's direction: "Artfully executed druggy flights of fancy include a hallucinatory macarena in a supermarket, a mind-reading black cat and a smart visual approximation of how it feels to be on the verge of throwing up. Here and elsewhere, Mr. Liman manipulates speed, light, editing and point of view vigorously and keeps the radio humming. He creates a film that lives up to the momentum of its title and doesn't really need much more."
The film has endured as a cult classic, with critics continuing to review the film. In 2008, Joe Valdez of The Distracted Globe wrote, "Few titles have the finesse to sum up a movie as brilliantly as Go, a drug fueled rollercoaster ride that alternates between dark comedy and light suspense with terrific verve. The film's appeal lies in its modest scale and the fact that it was made mostly by starving artist types. ...Nearly everyone involved in the production was a relative unknown or comer. With no pressure to supply an entertainment to the masses, the writer, director and most of the actors deliver the best work of their careers."
In April 2014, Joe Reid of The Atlantic revisited Go on the 15th anniversary of its release. Reid noted that at the time it came out, it was seen as a "knock-off" of other 1990s films. "The split-narrative style, complete with character title cards separating the film into thirds, put Go at the top of the list when it came to late-'90s Tarantino-influenced cinema. And then there was director Doug Liman, red hot off of the cult success of Swingers, trading neo-swing culture for X and raves. (Both films would give a healthy chunk of attention to Vegas, though.) The thing about Go that sets it apart, however, is that it's COMPLETELY FANTASTIC. Energetic and quotable and stylish and neither overly enamored with nor overly dismissive of the culture it's inhabiting."The Simpsons episode "Trilogy of Error" is, according to the writers' commentary, based on this film.